Oscillating lithotripter

ABSTRACT

A tip element for a lithotripter is provided. The tip element includes a proximal end configured for attachment to a waveguide of the lithotripter and a distal end configured for placement against at least one urinary tract stone. The lithotripter transmits energy from the tip element to the at least one urinary tract stone to break up the at least one urinary tract stone into fragments. The tip element may further include a tip element passage that extends between the proximal end and the distal end. The tip element passage communicates with a lumen of the waveguide for at least one of suctioning and irrigating a urinary tract. The distal end has one or more sharp edges to maintain contact between the at least one urinary tract stone and the distal end during suctioning. The distal end may be configured to limit the size of fragments from the at least one urinary tract stone drawn into the tip element passage during suctioning.

RELATED APPLICATION

The present application claims the benefit of U.S. Provisional PatentApplication No. 61/821,518, filed on May 9, 2013, the entire contents ofwhich are incorporated herein by reference.

FIELD

The present disclosure relates to a medical device, and moreparticularly to a lithotripter for fragmenting stones in a patient'sbody.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

Lithotripsy is a common method for fragmenting stones, or calculi, inthe urinary tract, kidneys, and/or bladder. Most lithotripsy devices useultrasound, laser, or pneumatic energy sources to fragment such stones.Typically, the lithotripter includes a shaft connected to anelectrically controlled driver or a pneumatic actuator. The shaft isinserted into the patient's anatomy to a location near the stone, and awaveform is sent through the shaft to impact the stone with the shaft tocreate a jackhammer or drilling effect on the stone, thus fragmentingthe stone into smaller elements that are easier to remove. The stonefragments are then removed by irrigation and/or baskets.

Among the literature that can pertain to this technology include thefollowing patent documents and published patent applications: US2006/0036168; US 2008/0287793; US 2010/0286791; US 2011/0251623;US2008/0188864; U.S. Pat. No. 7,229,455; U.S. Pat. No. 6,575,956; U.S.Pat. No. 4,721,107; U.S. Pat. No. 5,628,743; and U.S. Pat. No.8,226,629, all incorporated by reference for all purposes.

Current lithotripsy devices may be expensive, complicated, and/or lesseffective at fragmenting stones than desired. For example, certainlithotripsy methods may include the use of a first driver to provide afirst waveform to the stone through a first shaft and a second driver toprovide another waveform to the stone through a second shaft that isconcentrically mounted around the first shaft. Though insertion of alithotripter through the patient's urethra and ureter may be desired,such a device requires percutaneous access to the stone due to the largecombined shaft size. In another example, a single driver is used toprovide a waveform to the stone, however, the single waveform may notfragment the stone as well as desired.

Accordingly, there exists a need for more effective, simpler, smaller,and/or less expensive lithotripsy devices.

SUMMARY

The present disclosure provides an improved tip element for alithotripter.

In one aspect, the tip element includes a proximal end configured forattachment to a shaft or a waveguide of the lithotripter and a distalend configured for placement against at least one urinary tract stone.The lithotripter transmits energy from the tip element to the at leastone urinary tract stone to break up the at least one urinary tract stoneinto fragments. The tip element may further include a tip elementpassage that extends between the proximal end and the distal end. Thetip element passage communicates with a lumen of the waveguide for atleast one of suctioning and irrigating a urinary tract. The distal endhas one or more sharp edges to maintain contact between the at least oneurinary tract stone and the distal end during suctioning. The distal endis configured to limit the size of fragments from the at least oneurinary tract stone drawn into the tip element passage duringsuctioning.

The invention may be further characterized by one or any combination ofthe features described herein, such as: the waveguide is capable oftransmitting a sonic waveform with a sonic frequency and an ultrasonicwaveform with an ultrasonic frequency to the tip element; the tipelement has four countersunk sections extending from the distal end tothe proximal end; the distal end has four points and the tip element hasa crimped portion extending from the distal end towards the proximalend; the tip element has at least one slot extending from the distal endtowards the proximal end; the at least one slot is two slots or fourslots; the tip element has two angled slots extending from the distalend towards the proximal end; the tip element includes two sloped tabends; the tip element further comprises an insert positioned in the tipelement passage; the insert includes a sharp distal most edge; the tipelement has four angled slots extending from the distal end towards theproximal end; the tip element includes four sloped tab ends; the tipelement further comprises two inserts positioned in the tip elementpassage; one or both inserts includes a sharp distal most edge.

Further aspects, advantages and areas of applicability will becomeapparent from the description provided herein. It should be understoodthat the description and specific examples are intended for purposes ofillustration only and are not intended to limit the scope of the presentdisclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1A is a side cross-sectional view of a lithotripter for fragmentingstones, in accordance with the principles of the present disclosure;

FIG. 1B is a side cross-sectional view of an alternative embodiment ofthe lithotripter of FIG. 1A, in accordance with the principles of thepresent disclosure;

FIG. 2 is a block diagram of a closed loop feedback circuit for use withthe lithotripter of FIG. 1 or FIG. 3, according to the principles of thepresent disclosure;

FIG. 3A is a side cross-sectional view of another lithotripter forfragmenting stones, in accordance with the principles of the presentdisclosure;

FIG. 3B is a side cross-sectional view of an alternative embodiment ofthe lithotripter of FIG. 3A, in accordance with the principles of thepresent disclosure;

FIG. 3C is a side cross-sectional view of another alternative embodimentof the lithotripter of FIG. 3A, in accordance with the principles of thepresent disclosure;

FIG. 4 is a block diagram illustrating a method for fragmenting stones,according to the principles of the present disclosure;

FIG. 5 is a side cross-sectional view of yet another lithotripter forfragmenting stones, in accordance with the principles of the presentdisclosure;

FIG. 6A is a right side view of a motor coupler of the lithotripter ofFIG. 5, according to the principles of the present disclosure;

FIG. 6B is a left side view of the motor coupler of FIG. 6A, inaccordance with the principles of the present disclosure;

FIG. 6C is an end view of the motor coupler of the lithotripter of FIGS.6A-6B, according to the principles of the present disclosure;

FIG. 6D is a perspective view of the lithotripter of FIGS. 6A-6C, inaccordance with the principles of the present disclosure;

FIG. 7A is a cross-sectional view of a probe coupler of the lithotripterof FIG. 5, according to the principles of the present disclosure;

FIG. 7B is a side view of the probe couple of FIG. 7A, in accordancewith the principles of the present disclosure;

FIG. 7C is an end view of the probe coupler of FIGS. 7A-7B, according tothe principles of the present disclosure;

FIG. 7D is a perspective view of the probe coupler of FIGS. 7A-7C, inaccordance with the principles of the present disclosure;

FIG. 8 is a block diagram illustrating a lithotripter assembly for usewith the lithotripter of FIG. 5, in accordance with the principles ofthe present disclosure;

FIG. 9 is a graph illustrating a closed loop step of a lithotripterassembly for use with the lithotripter of FIG. 5, showing amplitude ofoscillation as a function of time, in accordance with the principles ofthe present disclosure;

FIG. 10 is a perspective view of one embodiment of the brushless DCmotor assembly of a lithotripter, in accordance with the principles ofthe present disclosure;

FIG. 11 is a perspective view of a motor coupler and probe coupler, inaccordance with the principles of the present disclosure;

FIG. 12 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 13 is a side view of the distal tip section of FIG. 12, inaccordance with the present disclosure;

FIG. 14 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 15 is a side view of the distal tip section of FIG. 14, inaccordance with the present disclosure;

FIG. 16 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 17 is a side view of the distal tip section of FIG. 16, inaccordance with the present disclosure;

FIG. 18 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 19 is a side view of the distal tip section of FIG. 18, inaccordance with the principles of the present disclosure;

FIG. 20 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 21 is a side view of the distal tip section of FIG. 20, inaccordance with the present disclosure;

FIG. 22 is a side view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 23 is a side view of the distal tip section of FIG. 22, inaccordance with the principles of the present disclosure;

FIG. 24 is an end view of one embodiment of a distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 25 is a side view of the distal tip section of FIG. 24, inaccordance with the present disclosure;

FIG. 26 is a side view of one embodiment of inserts to be placed into adistal tip section of a lithotripter, in accordance with the principlesof the present disclosure;

FIG. 27 is a side view of one embodiment of inserts to be placed into adistal tip section of a lithotripter, in accordance with the presentdisclosure;

FIG. 28 is a perspective view of the distal tip section of alithotripter, in accordance with the principles of the presentdisclosure;

FIG. 29 is an end view of a distal tip section of a lithotripter, inaccordance with the principles of the present disclosure;

FIG. 30 is a side view of a distal tip section of a lithotripter, inaccordance with the principles of the present disclosure; and

FIG. 31 is an end view of a distal tip section of a lithotripter, inaccordance with the principles of the present disclosure.

FIG. 32 is a side view of a distal tip section of a lithotripter, inaccordance with the principles of the present disclosure;

FIG. 33 is a perspective view of a distal tip section of a lithotripter,in accordance with the principles of the present disclosure;

FIG. 34 is a perspective view of a distal tip section of a lithotripter,in accordance with the principles of the present disclosure;

FIG. 35 is a perspective view of a distal tip section of a lithotripter,in accordance with the principles of the present disclosure; and

FIG. 36 is a perspective view of a distal tip section of a lithotripter,in accordance with the principles of the present disclosure.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Thepresent invention relates to a lithotripter for fragmenting stones.

A lithotripter for fragmenting a stone inside a patient's body isprovided. The lithotripter may include a motor (which may have multipledrivers) having at least two modes of operation. The motor is configuredto produce a first waveform and a second waveform. A wave guide shaft isconfigured to transmit the first and second waveforms to the stone. Insome forms, at least one of the first and second waveforms is providedto the stone at a frequency that is about equal to a natural frequencyof the stone.

With reference to the figures, wherein like numerals indicate likecomponents, and specifically with reference to FIG. 1A, an example of alithotripter in accordance with the principles of the present disclosureis illustrated and generally designated at 10. The lithotripter 10 maybe used for fragmenting stones in a patient's anatomy, such as in apatient's urinary tract, bladder, or kidneys.

The lithotripter 10 includes a driver housing 12 surrounding anultrasonic driver 14 and a sonic driver 16. Thus, the ultrasonic driver14 and the sonic driver 16 are disposed in a cavity 13 of the driverhousing 12. The ultrasonic driver 14 is configured to produce anultrasonic waveform having an ultrasonic frequency, and the sonic driver16 is configured to produce a sonic waveform having a sonic frequency.Lead wires 15 extend from the ultrasonic driver 14, and lead wires 17extend from the sonic driver 16, so that the ultrasonic driver 14 and/orthe sonic driver 16 may be excited by an electrical source (not shown).The sonic driver 16 is mechanically coupled to the ultrasonic driver 14,for example, by way of a connector 18. The connector 18 provides a rigidconnection between the ultrasonic and sonic drivers 14, 16. Herein thesonic driver 16 is comprised of the coil 153 and the magnet 152. Themagnet 152 is connected to the ultrasonic driver 14 by the connector 18.

A wave guide shaft 20 is provided for transmitting the ultrasonic andsonic waveforms to at least one stone, such as a urinary tract stone.For example, the wave guide shaft 20 may be partially inserted into thepatient through the patient's urethra or percutaneously by way of anincision through the patient's skin, by way of example. One or morewaveforms may be delivered to the stone by way of the end 22 of the waveguide shaft 20. The wave guide shaft 20 is driven by at least one of theultrasonic driver 14 and the sonic driver 16, in this embodiment.

In the present example, the ultrasonic driver 14 and the sonic driver 16are disposed in series within the driver housing 12. More specifically,the ultrasonic driver 14 has a proximal end 24 and a distal end 26, andthe sonic driver 16 has a proximal end 28 and a distal end 30. Theproximal end 24 of the ultrasonic driver 14 is disposed adjacent to thedistal end 30 of the sonic driver 16. The connector 18 contacts andconnects the distal end 30 of the sonic driver 30 and the proximal end24 of the ultrasonic driver 14. Thus, the sonic driver 16 is disposedadjacent to a proximal end 32 of the driver housing 12, and theultrasonic driver 14 is disposed adjacent to a distal end 34 of thedriver housing 12.

The sonic driver 16 is coupled to the wave guide shaft 20 via a linearbearing 36, and the ultrasonic driver 14 is coupled to the wave guideshaft 20 with a connector 38, and therefore, the wave guide shaft 20also couples the sonic driver 16 and the ultrasonic driver 14 together.It is contemplated that the linear bearing 36 may be made of plastic orother lightweight materials. A first spring 40 is connected to theproximal end 28 of the sonic driver 16 and the proximal end 32 of thedriver housing 12. A second spring 42 is connected to the distal end 26of the ultrasonic driver 14 and the distal end 34 of the driver housing12.

The lithotripter 10 has portions forming a lumen or channel therethroughfor at least one of suctioning and irrigating a urinary tract. Forexample, the wave guide shaft 20 has a lumen 44 formed through thecenter of the wave guide shaft 20 and extending along the length of thewave guide shaft 20. In addition, the housing 12 has openings 46 formedthrough both the proximal and distal ends 32, 34 of the housing 12, thesonic driver 16 has a channel 48 formed through the center of the sonicdriver 16, and the ultrasonic driver 14 has a channel 50 formed throughthe center of the ultrasonic driver 14. Accordingly, the wave guideshaft 12 extends through the housing 12 and the ultrasonic and sonicdrivers 14, 16. The wave guide shaft 20 may be rigid, semi-rigid, orflexible. Alternatively, rather than continuing uninterrupted throughthe entire assembly, the waveguide shaft may terminate proximally at orwithin the distal end 38 of the ultrasonic driver 14 and, as an integralelement of the ultrasonic driver, the central lumen 44 may continuetherethrough and terminate immediately after exiting the proximal end 24of the ultrasonic driver, as illustrated in FIG. 1B. The central lumen44 may continue on through the center of the sonic driver 16 as anattached tubular addendum to the central lumen at the proximal end 24 ofthe ultrasonic driver and terminate after exiting the proximal end ofthe housing 32 where it may connect to suction tubing for the purposesof removing waste procedural fluids and stone fragments. Tubularaddendum 51 of the central lumen 51 originating with the wave guideshaft 20 and continuing through the ultrasonic driver 14 may becomprised of an alternate material, such as plastic. The connectionbetween tubular addendum 51 of the central lumen and the proximal end 24of ultrasonic driver 14 may be configured to limit interference with theultrasonic vibration of ultrasonic driver 14. Other configurations ofthe central lumen 20 and various connection methods of central lumencomponents may be utilized to minimize dampening effects on theultrasonic vibration of the ultrasonic driver 14.

The ultrasonic and sonic drivers 14, 16 may take on various forms,without departing from the spirit and scope of the present invention.For example, the sonic driver 16 may be an electromagnetic lineardriver. By way of further example, the sonic driver 16 may be a voicecoil motor, a moving coil, a moving magnet, or a dual coil. Theultrasonic driver 14 may have a piezoelectric stack. In the exemplarylithotripter configuration presented in FIG. 1, the proximal and distalsprings are essential participating elements of the sonic driver'soperation, as is the mass of the ultrasonic driver, and will directlyaffect its operational characteristics. Low friction is an essentialelement of the sonic driver's efficient operation as the amount offriction opposing the free movement of the sonic driver and by way ofconnection the ultrasonic driver, will determine the spring forcerequired in the proximal and distal springs to properly control andrestore the position of the sonic driver during operation, the powerrequired to drive the sonic motor effectively, and potentially the wasteheat energy delivered into the lithotripter assembly and possibly theuser's hand.

In some forms, the sonic driver 16 is configured to produce the sonicwaveform at a frequency that oscillates at a natural frequency, orresonance frequency, of the targeted stone. For example, the sonicdriver 16 may be configured to produce the sonic waveform at a sonicfrequency that is about equal to a natural frequency, or resonancefrequency, of the targeted stone.

The sonic driver 16 may be adjustable to provide the sonic waveform atvarious frequencies. For example, the sonic driver 16 may be adjustableto provide the sonic waveform at a first frequency, a second frequency,and a third frequency. The first frequency may be in the range of about0.3-16 Hz, in the range of about 0.5-8 Hz, or in the range of about10-16 Hz, by way of example. The second frequency may be in the range ofabout 16-70 Hz, or in the range of about 40-70 Hz, by way of example.The third frequency may be in the range of about 70-200 Hz, or in therange of about 80-170 Hz, by way of example. The ultrasonic driver 14may be configured to provide the ultrasonic waveform at an ultrasonicfrequency in the range of about 20-30 kHz.

Regarding displacement of the waveforms, the ultrasonic driver 14 may beconfigured to produce a waveform of about 20 μm, or about 10-50 μm. Thesonic driver may be configured to produce a waveform of about 0.5-2 mm,which may be varied by the user. For example, in the first frequency,the sonic driver 16 may be configured to produce a first waveformmagnitude of about 1-2 mm; in the second frequency, the sonic driver 16may be configured to produce a second waveform magnitude of about 0.5-1mm; and in the third frequency, the sonic driver 16 may be configured toproduce a third waveform magnitude of about 0.5 mm.

It is contemplated that the sonic waveform's frequency and/or magnitudemay be selected based on the size of the targeted stone. For example,the first frequency and waveform magnitude may be selected for largerstones having a size of about 10-15 mm; the second frequency andwaveform magnitude may be selected for medium sized stones having a sizeof about 3-10 mm; and the third frequency and waveform magnitude may beselected for smaller stones having a size of about 1-3 mm. Though threeexamples are given, the sonic driver 16 may be configured to provide anynumber of selectable frequencies and magnitudes.

In some variations, the lithotripter 10 could include one or moreselectors to select between the various modes of the sonic driver 16.For example, the selector(s) could be configured to allow the user toselect the first, second, or third frequency and/or the first, second,or third waveform magnitude. The selector could include one or morebuttons, and/or a slider for fine tuning the selections. For example,the selector could include a first button for selecting the firstfrequency range and the first waveform magnitude range, and the firstranges could be further chosen with the use of a slider; likewise, theselector could include a second button for selecting the secondfrequency range and the second waveform magnitude range, and the secondranges could be further chosen with the use of the same slider or adifferent slider than the slider used for the first ranges; likewise,the selector could include a third button for selecting the thirdfrequency range and the third waveform magnitude range, and the thirdranges could be further chosen with the use of the same slider or adifferent slider than the slider used for the first and/or secondranges.

The lithotripter 10 may further include a stone size, mass, or densitydetector for detecting the size of a stone. For example, the stone size,mass, or density detector could include an optical detector and/or anultrasonic echo detector, the lithotripter being configured toautomatically set the sonic driver to provide the sonic waveform at oneof the first, second, and third frequencies based on the size, mass, ordensity of stone. The lithotripter 10 may be configured to set the sonicdriver 16 to provide the sonic waveform at the first frequency if thetarget urinary tract stone is greater than about 10 millimeters indiameter; the lithotripter 10 could be configured to set the sonicdriver 16 to provide the sonic waveform at the second frequency if thetarget urinary tract stone is greater than about 2-5 millimeters indiameter and less than or equal to about 10 millimeters in diameter; andthe lithotripter 10 could be configured to set the sonic driver 16 toprovide the sonic waveform at the third frequency if the target urinarytract stone is less than or equal to about 2-5 millimeters in diameter,by way of example.

The wave guide shaft 20 has a shaft length that is configured to deliverthe ultrasonic waveform at a maximum amplitude of the ultrasonicwaveform. For example, the shaft length may be provided in an incrementof a half ultrasonic wavelength of the ultrasonic waveform, such thatthe displacement is at the highpoint of the waveform at the distal end22 of the wave guide shaft 20. The maximum amplitude of the ultrasonicwaveform may be the amplitude that most optimally results in stonedestruction.

Referring now to FIG. 2, the lithotripter 10 could include a closed loopfeedback circuit 52 configured to determine a preferred ultrasonicfrequency that oscillates at a maximum amplitude, producing an anti-nodeor loop at the distal end 22 of the waveguide shaft 12. For example, thevoltage generated by the compression and distension of the piezoelectricelement of the ultrasonic driver 14 is captured and amplified by anamplifier (AMP) 54. The analog signal from the amplifier (AMP) 54 ispassed to an analog to digital (A/D) converter 56 and converted into a12-16 bit digital signal. This digital signal is passed to a digitalcomparator (COMP) 58 where it is compared to an incrementing ordecrementing reference generated by a microcontroller. The digital valueis adjusted relative to the reference and the previously read value andpassed to a digital to analog (D/A) converter 60. The analog signalgenerated by the digital to analog converter (D/A) 60 drives a voltagecontrolled oscillator (VCO) 62, which increases or decreases thefrequency accordingly. The output of the voltage controlled oscillator(VCO) 62 is amplified by a linear amplifier (AMP) 64 that drives thepiezoelectric stack of the ultrasonic driver 14. This way the loop isclosed. Once the maximum value is detected by the COMP 58 and theembedded algorithm, the frequency of the ultrasonic driver 14 will beset at its optimum value, for maximum amplitude, which will be deliveredto the stone 66 via the distal end 22 of the wave guide shaft 20.

The lithotripter 10 may also include a pulsator 68 configured to gatethe ultrasonic waveform. Thus, the ultrasonic driver 14 can be excitedwith a continuous signal of about 20-30 KHz or with a gated(interrupted) signal of about 20-30 KHz. The gating waveform is a squarewaveform with variable frequency (0.3-200 Hz) and duty cycle. In someembodiments, the duty cycle is about 80% on, 20% off. In someembodiments, the duty cycle is 50% on, 50% off. It is contemplated thatthe duty cycle may be in the range of 85-50% on, 15-50% off. This allowsthe application of pulsating ultrasonic energy at a selected frequencyand on/off duration. The frequency and duty cycle of the gating signalcan be user selectable. It is contemplated that the pulsating ultrasonicfrequency may be in phase with the gating signal.

The lithotripter 10 could have various modes of operation. For example,the lithotripter 10 could be operated in an ultrasonic only mode, suchthat continuous ultrasonic energy alone is transmitted to the targetedstone 66. The lithotripter 10 could be operated in a gated ultrasonicmode, such that the ultrasonic energy is gated with a square wave signalwith variable duty cycle and frequency of about 0.3-200 Hz (consistentwith the natural frequency of the targeted stone 66). The lithotripter10 could be operated in an oscillating ultrasonic mode, wherein thecontinuous ultrasonic energy is pulsated by the sonic driver 16 with adisplacement of about 0.5-2 mm and a frequency about 0.3-200 Hz(consistent with the natural frequency of the stone 66), depending onthe selected range. The lithotripter 10 could be operated in anoscillating gated ultrasonic mode, wherein gated ultrasonic energy ispulsated by the sonic driver 16 with a displacement of about 0.5-2 mmand a frequency about 0.3-200 Hz (consistent with the natural frequencyof the stone), depending on the selected range. The lithotripter 10could be operated in a low frequency impact mode, wherein only the lowfrequency of the sonic driver 16, of about 0.3-200 Hz, is transmitted tothe target stone 66 with low amplitude (1-2 mm) and high impact (5-10lb.) of force producing a jackhammer effect, and the ultrasonic driver14 is not used.

The ultrasonic and linear driver of the present invention are energizedwith oscillating frequencies which can be entirely independent or can besynchronized and manipulated in various ways. Energizing the drivers ina synchronized, swept-frequency and gated output method produces veryeffective results over more continuous and/or single frequencyenergizing methods. While the ideal ultrasonic resonant frequency isapplied, it is interrupted or gated in a continuously variable,repeating way, which may be a low-to-high ramped method in order toprovide beneficial lithotripsy results.

In one example, utilizing a frequency at the low end of the ranges todrive a shaft, coupled well with a larger stone (greater than 5 mm, forexample) with approximately 1-1.5 kg initial force effectively transfersthe sonic and gated ultrasonic energy into the body of the stone andoften causes the stone to crack into multiple pieces as the shaft tip isdriving through the stone. Smaller size stones are broken up more easilywith a mid-range frequency drive for both the oscillating low frequencylongitudinal translation drive and the gating of the ultrasonicresonance drive of the lithotripsy shaft and with less force, and thesmallest stones may be reduced to an easily evacuated size withfrequencies at the higher end of the frequency range with little to noapplied force. It is contemplated that sweeping through from the lowestto the highest end of the frequency range that is ideally optimized forthe type of stone encountered as well as for the size of the largestfragment, at a sweep rate that allows some duration of time in thevicinity of any one frequency or frequency band to allow the energy ofthat frequency or frequency band to couple into the stone fragmentseffectively to cause a more efficient stone breaking effect as the stoneor stone fragments experience strong ultrasonic and lower frequencyoscillatory energy that would match well with a resonance frequency ofthe stone material and/or that would exploit weaknesses in the structureof the stone.

As stone fragment size reduces, less force may be necessary to break thestone fragments into smaller pieces. The lithotripsy system may becoupled to an evacuation flow, or suction source, and thus it has beenseen that small stone fragments may be vacuumed up by the shaft tip andthe ultrasonic energy of the shaft tip may subsequently reduce the sizeof stone fragments too large to enter the inner diameter of thelithotripsy shaft into sizes that can be easily evacuated. It iscontemplated that the distal tip of the lithotripsy shaft may bedesigned to limit fragment size that may enter through the evacuationflow. Features at the distal end along these lines would help limit theoccurrence of stones which may get stuck along the exit pathway due toconstrictions or sharp direction changes in the outflow path or if thefragments are too large and may easily settle and interfere with theexit of future fragments.

In some forms, the distal end 22 of wave guide shaft 20 may be placed incontact with the stone 66 and having a jackhammer effect on the stone 66when one or more of the drivers 14, 16 are activated. However, in otherforms, the distal end 22 of the wave guide shaft 20 may be placedadjacent to, but not touching the stone 66. In some forms, the distalend 22 of the wave guide shaft 20 may gently touch the stone 66, butwithout a jackhammer effect, such that the oscillation breaks up thestone 66. Such a gentle contact may be preferred when the wave guideshaft 20 oscillates at or near the natural frequency of the stone 66.

Referring now to FIGS. 3A-3C, a variation of a lithotripter isillustrated and generally designated at 110. Like the lithotripter 10,the lithotripter 110 includes a driver housing 112 surrounding anultrasonic driver 114 and a sonic driver 116. Thus, the ultrasonicdriver 114 and the sonic driver 116 are disposed in a cavity 113 of thedriver housing 112. The ultrasonic and sonic drivers 114, 116 may havethe same operation and effect and be of the same type as described abovewith respect to the ultrasonic and sonic drivers 14, 16 of thelithotripter 10, and such discussion from above is herein incorporatedby reference in this section. Lead wires 115 extend from the ultrasonicdriver 114, and lead wires 117 extend from the sonic driver 116, so thatthe ultrasonic driver 114 and/or the sonic driver 116 may be excited byan electrical source (not shown). The sonic driver 116 is mechanicallycoupled to the ultrasonic driver 114, for example, by way of a connector118. The connector 118 provides a rigid connection between theultrasonic and sonic drivers 114, 116. Herein the sonic driver 116 iscomprised of the coil 153 and the magnet 152. The magnet 152 isconnected to the ultrasonic driver 114 by the connector 118.

In the present example, the ultrasonic driver 114 and the sonic driver116 are disposed concentrically with one another within the driverhousing 112. More specifically, the sonic driver 116 defines a cavity167 therein, and the ultrasonic driver 114 is disposed in the cavity 167of the sonic driver 116. The ultrasonic driver 114 has a proximal end124 and a distal end 126, and the sonic driver 116 has a proximal end128 and a distal end 130. The proximal end 124 of the ultrasonic driver114 is disposed adjacent to the proximal end 128 of the sonic driver 116within the cavity 167 of the sonic driver 116. The distal end 126 of theultrasonic driver 114 is disposed adjacent to the distal end 130 of thesonic driver 116 within the cavity 167 of the sonic driver 116. Thus,the proximal ends 124, 128 of the ultrasonic and sonic drivers 114, 116are disposed adjacent to a proximal end 132 of the driver housing 112,and the distal ends 126, 130 of the ultrasonic and sonic drivers 114,116 are disposed adjacent to a distal end 134 of the driver housing 112.The sonic driver may be a magnet 152 working with a coil 153 or set ofcoils 153,154.

The ultrasonic and sonic drivers 114, 116 are coupled to the wave guideshaft 120 via a linear bearing 136, and the ultrasonic driver 114 iscoupled to the wave guide shaft 120 with a connector 138. It iscontemplated that the linear bearing 136 may be made of plastic or otherlightweight materials. A first spring 140 is connected to one or both ofthe proximal ends 124, 128 of the ultrasonic and sonic drivers 114, 116,and the first spring 140 is connected to the proximal end 132 of thedriver housing 112. A second spring 142 is connected to one or both ofthe distal ends 126, 130 of the ultrasonic and sonic drivers 114, 116,and the second spring 140 is connected to the distal end 134 of thedriver housing 112. It is contemplated that either or both of theproximal and distal springs 140,142 may also be configured to act inplace of a linear bearing, axially supporting and guiding the movingdriver elements, thusly providing a linear bearing element functionwhile also providing a necessary mechanical spring element function.

The lithotripter 110 has portions forming a lumen or channeltherethrough for at least one of suctioning and irrigating a urinarytract. For example, the wave guide shaft 120 has a lumen 144 formedthrough the center of the wave guide shaft 120 and extending along thelength of the wave guide shaft 120. In addition, the housing 112 hasopenings 146 formed through both the proximal and distal ends 132, 134of the housing 112, and the ultrasonic and sonic drivers 114, 116 have achannel 147 formed through the center of the ultrasonic and sonicdrivers 114, 116. Accordingly, the wave guide shaft 112 extends throughthe housing 112 and the ultrasonic and sonic drivers 114, 116. The waveguide shaft 120 may be rigid, semi-rigid, or flexible. Alternatively,rather than continuing uninterrupted through the entire handpieceassembly 112, the waveguide shaft 120 may terminate proximally at orwithin the distal end 38,138 of the ultrasonic driver 114 and, as anintegral element of the ultrasonic driver 114, the central lumen 144 maycontinue therethrough and terminate immediately after exiting theproximal end 124 of the ultrasonic driver, as illustrated in FIGS. 3Band 3C. The central lumen 144 may continue on through the center of thesonic driver 116 as an attached tubular addendum to the central lumen atthe proximal end 124 of the ultrasonic driver and terminate afterexiting the proximal end of the housing 132 where it may connect to asuction tubing via suction connector 175 for the purposes of removingwaste procedural fluids and stone fragments. Tubular addendum of thecentral lumen 151 originating with the wave guide shaft 120 andcontinuing through the ultrasonic driver 114 may be comprised of analternate material, such as plastic. The connection between the tubularaddendum of the central lumen 151 and the proximal end 124 of theultrasonic driver 114 may be configured to limit interference with theultrasonic vibration of the ultrasonic driver 114. Other configurationsof the central lumen 144 and various connection methods of central lumencomponents may be utilized to minimize dampening effects on theultrasonic vibration of the ultrasonic driver 114.

The rest of the description and operation of the lithotripter 10, whichis not described as being different than the lithotripter 110 may beapplied to the lithotripter 110, and such discussion is hereinincorporated by reference into this section. For example, the closedloop feedback circuit of FIG. 2 may be applied to and used by thelithotripter 110 of FIG. 3.

Referring now to FIG. 4, a method of fragmenting urinary tract stonesusing a lithotripter as claimed herein, such as the lithotripter 10, 110described above, is illustrated and generally designated at 100. Themethod 100 includes a step 102 of determining a size, determining atype, or determining both a size and type of a urinary tract stone 66.The method 100 further includes a step 103 of selecting a magnitude of asonic frequency for producing a sonic waveform, the magnitude of thesonic frequency being selected based on the size or type of the urinarytract stone 66. For example, the magnitude of the sonic frequency may beselected to correspond to the natural frequency of the target stone 66.The method 100 includes a step 104 of producing the sonic waveform usinga sonic driver 16, 116. The method 100 includes a step 105 of producingan ultrasonic waveform having an ultrasonic frequency using anultrasonic driver 14, 114. The steps 104, 105 may be completedsimultaneously, if desired, or alternatively, serially. The method 100includes a step 106 of transmitting the sonic waveform and theultrasonic waveform to the urinary tract stone 66 via a wave guide shaft20, 120.

When performing the method 100, the magnitude of the sonic frequency maybe provided at about the natural frequency of the urinary tract stone66. In addition, or in the alternative, the magnitude of the sonicfrequency may be selectable from at least a low sonic frequency, amedium sonic frequency, and a high sonic frequency. For example, the lowsonic frequency may be provided in the range of about 0.3-16 Hz, themedium sonic frequency may be provided in the range of about 16-70 Hz,and the high sonic frequency may be provided in the range of about70-200 Hz. The ultrasonic frequency may be provided in the range ofabout 20-30 kHz. The ultrasonic waveform may be provided having anultrasonic waveform amplitude in the range of about 10-50 micrometers,and the sonic waveform may be provided having a sonic waveform amplitudein the range of about 0.5-2 millimeters.

The method 100 may also include suctioning and/or irrigating a urinarytract through a lumen 44, 144 extending through the wave guide shaft 20,120 and thus, through channels 48, 50, 147 formed in the ultrasonic andsonic drivers 14, 114, 16, 116.

In addition, the method 100 may include electronic gating the ultrasonicwaveform with a square wave of variable frequency and duty cycle, asdescribed above.

Referring now to FIG. 5, a variation of a lithotripter is illustratedand generally designated at 210. The lithotripter 210 is configured tofragment a stone in a patient's body, such as in a patient's ureter,kidney, or bladder. The lithotripter 210 includes a housing 212 having abrushless DC motor 214 disposed in the housing 212. The brushless DCmotor 214 is operable to produce a rotational motion. The brushless DCmotor 214 may be autoclavable and may have three Hall Effect sensors, byway of example. The motor 214 may be mounted into a holder portion 215of the housing, for example, with threading.

A motor shaft 216 extends from a rotor of the brushless DC motor 214 andis operable to be rotated along a longitudinal axis X of thelithotripter 210. A motor coupler 218 is attached to the motor shaft216, which is also illustrated in FIGS. 6A-6D. For example, as shown inFIGS. 6A-6D, the motor coupler 218 is annular and has an extension 219extending from an end face 221. The motor coupler 218 may be formed ofhard steel.

A probe coupler 224 having a cam surface 226 is disposed in the housing212 adjacent to the motor coupler 218. The probe coupler 224 is alsoillustrated in FIGS. 7A-7D. For example, the probe coupler has anelongate cylindrical shaft 225 extending from an end 227. The end 227has the cam surface 226 formed thereon. The probe coupler 224 (includingthe cam surface 226) and the motor coupler 218 form a mechanical motionconverter, wherein the rotational motion produced by the motor 214 isconverted to a linear oscillating motion of the probe coupler 224,producing a linear waveform. It is contemplated that the cam surface 226may be sloped to encourage production of a greater shock.

A spring 228 biases the probe coupler 224 into contact with the motorcoupler 218, and when the motor coupler 218 is rotated, it slides alongthe cam surface 226 and causes the probe coupler 224 to move back andforth along the longitudinal axis X. It is contemplated that the spring228 may further comprise a dampening feature. The extensions 219 of themotor coupler 218 contact the cam surface 226 of the probe coupler 224as the motor coupler 218 rotates about a center of the motor coupler218. The motor coupler 218 therefore pushes the probe coupler 224 alongthe longitudinal axis X of the lithotripter 210 in one direction alongthe longitudinal axis, and the spring 228 biases the probe coupler 224in the opposite direction along the longitudinal direction X, therebymoving the probe coupler 224 in the opposite direction when theextension 219 of the motor coupler 218 is rotated away from a highportion 231 of the cam surface 226. It is contemplated that the camsurface may be sloped to create a greater shock. It is contemplated thatthe cam surface may be hardened and ground to reduce wear potential. Alinear bearing 229 may be disposed adjacent to the spring 228, whichreduces the friction of linear movement. It is contemplated that linearbearing the 229 may be made of plastic or other lightweight materials.

A wave guide shaft 220 is coupled to the probe coupler 224. The waveguide shaft 220 is configured to transmit the linear waveform to atarget stone. For example, when the distal end 222 of the wave guideshaft 220 is placed into contact with a target stone, it may produce ajackhammer effect thereon. Thus, the housing 212 may be a handle and thewave guide shaft 220 extends therefrom.

It is contemplated that in some embodiments the motor shaft 305 may beseparate from a cam shaft 302 as depicted in FIGS. 10-11. Isolating themotor shaft 305 from the cam shaft 302 may serve to protect theintegrity of the motor over time, as illustrated in FIG. 10. It iscontemplated that a gear assembly 310 would transfer energy from theBLDC motor shaft 305 to the cam shaft 302. This gear assembly 310 may bein a 1:4 ratio, allowing for amplification of the energy output from themotor. The cam shaft 302 may include a dampening mechanism 312 at aproximal end, which may include a section of silicone and may be furthersupported with an internal spring within the section of silicone placedbetween the cam pair 311 and the lithotripsy shaft 320, formed togetherto surround the cam shaft 302 and provide dampening of the vibrationaland/or linear motion during operation. It is contemplated that bearingsand silicone may be provided at points where the cam shaft 302 and motorshaft 305 connect into the housing 300. In some embodiments, a motorcoupler 318 is provided with a motor coupler attachment block 316 whichallows for the option of swapping out a cam pair 311, which representsthe transfer point between motor coupler and shaft coupler, to correctfor wear during regular maintenance, for example. The motor coupler 318and the motor coupler attachment block 316 may be easily loosened andremoved using set screws 315 in order to insert a replacement motorcoupler 318. It is contemplated that a suction or irrigation capabilitymay be provided through the cam shaft 302 as this shaft is locatedtoward a centerline of the device.

FIG. 11 illustrates a close up view of the motor coupler 318 and theprobe coupler 324. The motor coupler 318 (including end surface 321) isdisposed in the housing 300 adjacent to the shaft coupler 324 (includingthe cam surface 326). The motor coupler 318 is removable andreplaceable, in some embodiments, by loosening the set screws 315 in themotor coupler attachment block 316. The motor coupler connects to thecam shaft 302 and the probe coupler connects to the wave guide shaft320.

The lithotripter 210 may be provided as part of a lithotripter assembly211 that also includes a controller 270, or driver/amplifier (see FIG.8). The controller 270 may be configured to operate the brushless DCmotor 214 in at least a first mode of operation and a second mode ofoperation. The first mode of operation may be an over-shoot impulse modeand the second mode of operation may be a high speed rotational mode.

For example, the brushless DC motor 214 has a rotor coupled to therotational shaft 216. In the over-shoot impulse mode, an impulse torqueis generated by the brushless DC motor by moving the rotor in a partialrotation; the rotor and the rotational shaft 216 may be moved in atleast one step of less than a full rotation of the rotor to generate atorque on the wave guide shaft 220. In one example, the rotor androtational shaft 216 may be moved in a plurality of back-and-forth stepsof between about ten and thirty degrees, or about 15 degrees in theover-shoot impulse mode, which provides a high torque on the wave guideshaft 220. In the over-shoot impulse mode, the controller 270 works on acurrent mode and a large amplify gain is applied to the current loop.For example, a current of about 20 Amps could be applied to thecontroller 270 for a short period. Accordingly, a high torque can beapplied to the stone 66 with the over-shoot impulse mode, which can havea ballistic effect on the stone 66. The amplify gain can be programmedto adapt to different size stones, using the feedback loop illustratedin FIG. 8.

In the high speed rotational mode, the brushless DC motor 214 operatesthe rotor and rotational shaft 216 in a continuous rotational motion. Aconstant control voltage may be applied to the amplifier of thecontroller 270, and the motor 214 may rotate at a speed of up to about50,000 rpm or even 60,000 rpm. Therefore, in the high speed rotationalmode, the rotor and rotational shaft 216 may rotate of speeds of about40,000 to about 60,000 rpm. In one variation, a voltage of about 0-10 Vmay be applied to the controller 270, for example, about 5V, in the highspeed rotational mode.

Referring to FIG. 9, a graph 400 illustrates the amplitude of theoscillation of the wave guide shaft 220 as a function of time. When thelithotripter 210 is in the over-shoot impulse mode, a high amplitude ofoscillation is provided for a short period of time, as illustrated bythe impulse mode plot line 404. When the lithotripter 210 is in the highspeed rotational mode, a moderate and continuous amplitude is providedas illustrated by the rotational plot line 403. Plot line 402 shows themotion of the motor 14 when a small proportional gain is applied in thecontroller 270.

Referring again to FIG. 8, the controller 270 may be aproportional-integral-derivative (PID) controller, having a proportional272, integral 274, and derivative 276 control logic. The lithotripterassembly 211 may also include a position feedback sensor 278, such as anoptical encoder, to determine the position of the rotor of the motor214. The position feedback sensor 278 is configured to provide rotorposition data to the PID controller 270. The position sensor may providethe rotor position date to a summation point 280 within the PIDcontroller, which then updates the control logic and provides thecontrol logic to a summation point 282 and ultimately to the motor 214.A power source 284 provides a power input to the controller 270, whichmay be capable of providing a high power for the over-shoot impulse modeand a lower power for the high speed rotational mode, or vice versa.

Thus, in the over-shoot impulse mode, the motor 214 is driven by a highperformance servo driver 270 in current mode. The position sensor 278 islocated in the update loop. The loop may be set to repeat at 0.5 msintervals, for example. The torque provided may be explained by thefollowing equation: τ=Kp(θ2−θ1)+Kd(ω2−ω1), where τ is the torqueprovided to the stone 66 via the wave guide shaft 220, Kp is theproportional gain, θ2 is the rotor final angular position in one loop,θ1 is the initial rotor angular position in one loop, Kd is thederivative gain, ω2 is the final angular velocity of the rotor in oneloop, and ω1 is the initial angular velocity of the rotor in one loop.ω2=dθ2/dt and ω1=dθ1/dt.

In some embodiments where the cam shaft 302 is positioned along aseparate longitudinal axis from a central axis of the motor shaft 305and a gear assembly 310 is provided to transfer energy between the camshaft 302 and the motor shaft 305, torque values may range from about112 mNm to about 144 mNm for a spur gear with gear ratio 1:4. Resultingrotational speeds for this embodiment would range from about 2500 rpm toabout 7500 rpm.

As in the examples above, the oscillation of the wave guide shaft 220,320 may be provided to the stone 66 at a frequency that is about equalto the natural frequency of the stone 66.

The natural frequency of the stone may vary based on stone size. It iscontemplated that various modes of operation may be employed with thelithotripter described herein. By way of example, three ranges may beprovided as described above or may be more generalized as small stonemode, large stone mode, and general mode. Small stone mode may provideoscillation frequencies in the range of 17-170 Hz, for example. Largestone mode may provide oscillation frequencies in the range of 0.5-17Hz, for example. General mode may provide oscillation frequencies in therange of 0.5-170 Hz, for example.

In an automatic mode of operation, the device may start with operationin general mode and then upon detection of a large stone or small stonethrough use of a sensor, for example, proceed to operate in that mode.If at first a large stone mode is utilized, the device may switch tooperation in a small stone mode after a predetermined period of time,such as 30 seconds to 1 minute, for example.

In another embodiment, a manual mode of operation may be utilized. Inthis mode, a user may select whether or not to operate in large stonemode, small stone mode, or general mode based on direct observationthrough the distal tip of an endoscope, for example.

It is further contemplated that the device may be provided with a sharptip which may facilitate stones maintaining contact with the tip duringlithotripsy after use of a suction function to attract a stone to thedistal end of the device and may further limit size of outgoingfragments during active lithotripsy and may help to enhance the stonefree rate by producing smaller particle sizes which can be removed bysuction through the lithotripsy shaft 20. It is contemplated that a tipelement passage may be provided with various alternative configurations,including a four point crimped tip with countersunk sections, a fourslot angled tip with sloped tab ends, a four slot angled tip with slopedtab ends and one side of the tabs bent in, a tip with two slots cut intoopposing sides, a divided tip with an optional insert, and a tip withfour slots cut in and two inserts with sloped tab end faces. Examples ofsuch tip elements are provided in FIGS. 12-28.

FIGS. 12-13 illustrate an end and a side view of a distal end of anexample embodiment of a tip element which may be provided on wave guideshaft 20 at a distal end 22. A crimped tip 330 is combined withcountersunk sections which extend from the distal end 22 toward theproximal end of the wave guide shaft 20.

FIGS. 14-15 illustrate an alternative embodiment which includes acrimped tip 330 provided at the distal end 22 of the wave guide shaft20.

FIGS. 16-17 illustrate an alternative embodiment which includes fourslots 335 provided at a distal end and also includes angled tip regions332 at the distal end 22 of the wave guide shaft 20. FIGS. 18-19illustrate an alternative embodiment which includes sloped tab ends 333as well as bent in portions 334, which add an element of contouring tothe distal most region which may provide an additional distribution ofsharp surfaces for kidney stones to maintain contact with the distal end22, of the shaft 20. This embodiment illustrates the tabs bent in at oneedge in order to reduce the cross-sectional opening area of the tube toreduce the size of the stone fragments entering the tube, increase theaffected area of the stone being fragmented, provide a wedging effect tomore effectively split up a stone and reduce the overall size of thestone fragments produced. The inclusion of side slots also improvesirrigation and enhances the evacuation of smaller stone debris whichmight otherwise intervene between the shaft tip and the stone beingfragmented and thus reduce the lithotripter's stone fragmentingeffectiveness by dampening the direct impact of the lithotripter shafttip on the stone being fragmented.

FIGS. 20-21 illustrate an additional alternative embodiment in which aninsert 336 is placed into slots 335 and an angle 332 is applied to thedistal most region 22 of the wave guide shaft 20. This embodimentillustrates the addition of a cross-member in order to reduce thecross-sectional opening area of the tube to reduce the size of the stonefragments entering the tube, increase the affected area of the stonebeing fragmented and more effectively split up a stone and reduce theoverall size of the stone fragments produced. Inclusion of side slotscould also improve irrigation and enhance the evacuation of smallerstone debris which might otherwise intervene between the shaft tip andthe stone being fragmented and thus reduce the lithotripter's stonefragmenting effectiveness by dampening the direct impact of thelithotripter shaft tip on the stone being fragmented. In this examplethe insert is wider at the face of the tube than it is down inside thetube, to reduce the possibility of clogging at the tip by providing anever widening cross-section from the distal face of the shaft tip to theproximal direction of the shaft. Inserts such as this may be brazed orwelded to the lithotripsy shaft to secure them in place.

FIGS. 22-23 illustrate an embodiment where one or more insert slots maybe provided with interlocking or retaining features for maintaining aposition of the insert in slots 335 within the distal tip 22 of thelithotripter shaft tip. Interlocking features may include grooves,beveled edges, or tabs and slots. These mechanical retaining featuresare meant to assist in placement of the inserts as well as augmentretention of the inserts in addition to welding or brazing or the likeof the inserts to the lithotripsy shaft.

FIGS. 24-25 illustrate an alternative embodiment in which two inserts336 are placed perpendicularly with respect to each other into slots 335to improve fragmentation effectiveness and further limit kidney stoneparticle size which may enter the wave guide shaft 20 during activesuction. Edges of the inserts 336 may additionally be provided withsharp surfaces 338 for enhancing the ability of stones to maintaincontact with the distal end 22 as well as fragment stones moreeffectively. In this embodiment, shaft tabs are additionally providedwith an angled tip 332 to more effectively engage with the surface of astone. The inserts may be wedged shaped with a narrower proximal edge toreduce the possibility of clogging.

FIGS. 26-27 represent an embodiment of inserts with interlockingfeatures of the distal end 22 of the waveguide shaft 20. A left insertmay be rotated and placed on top of a right insert such that they form atight immovable fit through the use of interlocking features, in thepresent example via slots cut into the inserts.

FIGS. 28-30 represent an alternative embodiment of the distal end 22 ofthe wave guide shaft 20 with a crimped tip 330. The crimped tip 330 isprovided with sharp corners 337 and pointed edges 338 to enhance theability of kidney stones to maintain contact to waveguide shaft 20during stone breaking or active suction. A smaller distal openingreduces the size of the evacuated fragments.

Similarly to FIGS. 18-19 but with a thinner side wall, FIGS. 31-32illustrate an alternative embodiment of sharp features which may beprovided to the distal end 22 to wave guide shaft 20. Four slots 335 arecut extending from the distal end 22 towards the proximal end andsloping 333 and angling 332 is provided at the tip ends.

FIGS. 33-36 show lithotripsy shaft tips which have been modified from aflat terminal face by various beveling or angled cutting methods. FIGS.33-34 illustrate simple external, planar beveling of a lithotripsy shafttip. This type of tip provides sharp points and edges for “digging into”stone surfaces as well as wedging action for splitting stones apart.FIGS. 35-36 present examples of lithotripsy shaft tip faces which havehad multiple, angled cuts made, producing sharp, pyramidal and/or ridgedpoints or edges which would enhance the ability of such tips to “dig in”to a stone surface. In both these examples, a tube tip could beaugmented with bending or additional material via brazing, welding orthe like prior to the surface modification so that an opening smallerthan the original tube's internal diameter may be presented, to limitthe size of the stone fragments entering the tube during suction. Thetype of tip configurations represented in FIGS. 35-36 are expected tohave a lower possibility of inadvertent tissue damage due to directcontact as the pointed elements are more numerous, closely positionedand effectively less aggressive than those examples represented in FIGS.33-34, for example.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention. For example, variations in the various figures can becombined with each without departing from the spirit and scope of thepresent disclosure.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize, however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

Any numerical values recited in the above application include ail valuesfrom the lower value to the upper value in increments of one unitprovided that there is a separation of at least 2 units between anylower value and any higher value. As an example, if it is stated thatthe amount of a component or a value of a process variable such as, forexample, temperature, pressure, time and the like is, for example, from1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it isintended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc.are expressly enumerated in this specification. For values which areless than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1as appropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner.

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints, the use of “about” or “approximately” inconnection with a range apply to both ends of the range. Thus, “about 20to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes.

The term “consisting essentially of” to describe a combination shallinclude the elements, ingredients, components or steps identified, andsuch other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination.

The use of the terms “comprising” or “including” describing combinationsof elements, ingredients, components or steps herein also contemplatesembodiments that consist essentially of the elements, ingredients,components or steps.

What is claimed is:
 1. A tip element for a lithotripter, the tip elementcomprising: a proximal end configured for attachment to a waveguide ofthe lithotripter, the lithotripter comprising an evacuation lumen, theevacuation lumen capable of supporting active suction; a distal endconfigured for placement against at least one urinary tract stone, thelithotripter transmitting energy from the tip element to the at leastone urinary tract stone to break up the at least one urinary tract stoneinto fragments; a tip element passage extending between the proximal endand the distal end, the tip element passage communicating with a lumenof the waveguide for at least one of suctioning and irrigating a urinarytract, the tip element having at least one slot with angled sidesextending from the distal end towards the proximal end along the lengthof the slot; and an insert positioned in the tip element passage, theinsert including a sharp distal most edge, wherein the distal end hasone or more sharp edges to maintain contact between the at least oneurinary tract stone and the distal end during active suction.
 2. The tipelement of claim 1, wherein the distal end is configured to limit thesize of fragments from the at least one urinary tract stone drawn intothe tip element passage during suctioning.
 3. The tip element of claim1, wherein the waveguide is capable of transmitting a sonic waveformwith a sonic frequency and an ultrasonic waveform with an ultrasonicfrequency to the tip element.
 4. The tip element of claim 1, wherein thetip element has one or more countersunk sections extending from thedistal end of the tip element to the proximal end of the tip element. 5.The tip element of claim 1, wherein the at least one slot is two slots.6. The tip element of claim 5, wherein the tip element includes twosloped tab ends.
 7. The tip element of claim 1, wherein the at least oneslot is four slots.
 8. The tip element of claim 7, wherein the tipelement includes four sloped tab ends.
 9. The tip element of claim 8further comprising a second insert positioned in the tip elementpassage.
 10. The tip element of claim 9, wherein one or both insertsincludes a sharp distal most edge.
 11. A tip element for a lithotripter,the tip element comprising: a proximal end configured for attachment toa waveguide of the lithotripter, the lithotripter comprising anevacuation lumen, the evacuation lumen capable of supporting activesuction; a distal end configured for placement against at least oneurinary tract stone, the lithotripter transmitting energy from the tipelement to the at least one urinary tract stone to break up the at leastone urinary tract stone into fragments; a tip element passage extendingbetween the proximal end and the distal end, the tip element passagecommunicating with a lumen of the waveguide for at least one ofsuctioning and irrigating a urinary tract, the tip element having atleast one slot with angled sides extending from the distal end towardsthe proximal end along the length of the slot; and an insert positionedin the tip element passage, the insert including a sharp distal mostedge, wherein the distal end has one or more sharp edges to maintaincontact between the at least one urinary tract stone and the distal end.